From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Magenheimer Subject: Re: 32bit xen and "claim" Date: Thu, 1 Nov 2012 13:55:10 -0700 (PDT) Message-ID: <75058642-ad3b-4df9-a24a-7dbdc5f6e8c5@default> References: <620abc58-07b9-4102-b883-0bfcd8e78471@default> <5092DE7E020000780008EB96@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5092DE7E020000780008EB96@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich , keir@xen.org Cc: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org > From: Jan Beulich [mailto:jbeulich@suse.com] > Sent: Thursday, November 01, 2012 2:42 PM > To: Dan Magenheimer; keir@xen.org > Cc: xen-devel@lists.xen.org > Subject: Re: 32bit xen and "claim" > >If the CONFIG_X86/separation code will no longer be used, > >shall I submit a patch to delete the code in page_alloc.c > >and memory.c? Or can you (Keir or Jan) just delete it? > > Please don't. OK. I'm glad I asked rather than assuming. > >when prototyping the "claim" hypercall/subop, can I assume > >that the CONFIG_X86 code in the hypervisor and, specifically > >any separation of the concepts of xen_heap from dom_heap, > >can be ignored? > > No, you shouldn't. Once adding support for memory amounts beyond 5Tb > I expect the separation to become meaningful even for x86-64. On quick scan, I don't see anything obvious in the archives that explains why 5Tb is the limit (rather than, say, 4Tb or 8Tb, or some other power of two). Could you provide a pointer to this info or, if you agree it is non-obvious and undocumented, say a few words of explanation? Also, just wondering, should exceeding 5Tb be on the 4.3 features list or is >5Tb physical memory still too far away? Thanks, Dan